cushion, suppress, kill, mute, dull, muffle, stifle, silence, blunt, dampen, deaden, numb, cool (down), stultify, quiet, desensitize, develop a thick skin, inure, accustom (someone to something unpleasant), suck the soul out of, insensitize, enfeeble, deafen

contract, slide, slump, break down, dismantle, slip, wane, weaken, sink, plummet, deteriorate, fizzle, tank, bottom out, compound, decline, plunge, flag, turn into/out, erode, degenerate, worsen, lapse into, strip of, take down/apart, devolve into, expunge, go downhill, go to pot, fade away/out

hollow out, squash, quash, thin, water down, beat down, weaken, endanger, jeopardize, encumber, impair, undermine, sap, suck out, incapacitate, exhaust, erode, blunt, drain (of vitality), enervate, starve, grind down, tax (one's reserves), hit someone hard, wind (one from exertion), tire someone out, debilitate, fatigue, wear out/down, devitalize, eat away, chip away at, weary, defang

chip away, slash, shave off, trim, flatten, contract, abrade, shed, whittle, chisel, lower, shrink, thin, reduce, narrow, divide, deduct, consume, apportion, skimp, scale back/down, economize, hemorrhage (money/staff), shorten, minimize, lessen, dwarf, prune, pare (down), diminish, cut (back/down), cut costs, slim down (the budget), abridge, stunt, truncate, take away, compact, restrict (growth), ratchet down, subtract, subdivide, miniaturize, foreshorten, rightsize

crack, wind up, split, break down, fade, collapse, spin out of control, plummet, disintegrate, backfire, deteriorate, screw up, fizzle, fail, waste, hit bottom, tank, bottom out, decline, teeter, erode, hang one's head, regret, end up, wear someone down, resign oneself (to fate), lose (work/hope), ruin (relationships), rack with